bcm53xx: use -ENOENT error for TRX parser workaround patch

Change return value from -EINVAL to -ENOENT for the TRX parser
workaround patch as it's better suited and it's the common exit error
for parser failing parsing for expected condition (partition not init,
zero partition found in the schema, magic values not matching)

Also this is needed for a pending upstream patch that will permit parser
to fail and be skipped for subpartitions only with the -ENOENT error.

Signed-off-by: Christian Marangi <[email protected]>

target/linux/bcm53xx/patches-6.6/140-mtd-parsers-trx-parse-firmware-MTD-partitions-only.patch

@@ -36,7 +36,7 @@ Signed-off-by: Rafał Miłecki <[email protected]>
  
 +	/* Don't parse any failsafe / backup partitions */
 +	if (strcmp(mtd->name, "firmware"))
-+		return -EINVAL;
++		return -ENOENT;
 +
  	parts = kcalloc(TRX_PARSER_MAX_PARTS, sizeof(struct mtd_partition),
  			GFP_KERNEL);